Language impairment (LI) is not a unitary disorder and recent developmental results call into questions the language-specific nature of this disorder. These include deficits in attention, visuospatial processing and affect. Also, neurologic findings have revealed that some LI children have dysfunctional nervous systems as indicated by abnormal motor abilities as well as abnormalities of brain structure (MRI) and function (ERP). In the next funding period, Project 1 has several goals: To clarify the nature of language impairment through detailed studies of morphology, syntax, narratives, and affect and through real-time language processing studies of a range of levels (work, sentence, discourse context), structures (morphology, syntax, semantics), and modalities (comprehension and production). To identify nonlinguistic deficits associated with LI through studies that examine spatial memory for location, memory for configural information, nonlinguistic visual and auditory selective attention, shifts of attention, and executive functions. To contrast LI neurobehavioral profiles with profiles from high-function children with autism to enhance our ability to detect associations and dissociations between selective aspects of language and nonlinguistic cognition. To characterize the neurologic bases of LI through detailed neurologic examinations and studies of MRI and ERP in collaboration with Multicenter investigators and relate findings to language and cognitive profiles. Our studies will reveal a great deal about athe patterns of impairment and sparing of linguistic and cognitive functioning in children. Each study domain has its roots in psycholinguistics, cognitive neuroscience, and neuropsychology and will provide unique information about plasticity and specificity in brain organization for language and cognition. Finally, detailed developmental findings coupled with findings from the studies of brain structure and brain function can provide important insights into the causal factors related to language impairment serving to guide more precise diagnosis and treatment in the future.